ya' pulled the crt? ok....but remember to be very very careful when handling that hv ribbon. after you mess with them they are liable to start arcing. some say they have had luck with cleaning them with ipa. in my experience that just made them worse. bending them too much can cause them to delaminate (they are getting pretty brittle), and then you are screwed.
and remember "the +100 volt supply is independent and provides a reference voltage for the -100 volt supply. the +248 and -12.6 volt supplies are dependent on the -100v supply for reference voltages". start with the +100 then work on the -100 then the others.
good luck and keep one hand in your pocket when probing. better yet.....connect the probes when powered down and stand back to observe when powering up.
A summary of what i've done and intend to do, with reasons.
Opened it, checked the voltages and decided i'd start with the capacitors.
Couldn't figure out what magic they used to make that cap board stay in place.
Can't think of anything else to do so in desperation i pull the CRT, their idea not mine.
With the knowledge gained into how they think i suddenly figured out the capacitor boards mount.
What i'm going to do;
Replace that 3 wire ribbon because it needs to go. If it didn't before it does now.
Replace all the main capacitors just to be safe.
Reinstall CRT.
Carefully power up, pray i didn't screw too much up and check the voltages again if needed.
Go from there dependent upon results.